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Networking Topologies and Connectors

Jul 18, 2024

Networking Topologies and Connectors

Topologies

  1. Star Topology

    • Structure: All devices connect to a central wiring point (hub or switch).
    • Pros: Failure of one computer/cable doesn't affect others.
    • Cons: Central hub/switch failure affects entire network (single point of failure).

  2. Bus Topology

    • Structure: Devices connect to a single cable/backbone (coaxial cable).
    • Pros: Cheap and easy to implement.
    • Cons: Requires terminators; signal reflection if cable is open.

  3. Ring Topology

    • Structure: Computers form a closed loop/ring, each having two neighbors.
    • Pros: Easy to install and troubleshoot.
    • Cons: Single computer/cable break disrupts entire network.

  4. Mesh Topology

    • Structure: Each computer connects to every other computer.
    • Pros: High redundancy; network communication remains even if multiple connections fail.
    • Cons: Expensive due to high cabling and network cards cost.

  5. Hybrid Topology

    • Structure: Combination of topologies (e.g., Star-Bus, Star-Ring).
    • Pros: Combines advantages of multiple topologies.

  6. Point-to-Point Topology

    • Structure: Direct connection between 2 hosts using a single cable.
    • Usage: Simple, suitable for direct communication between devices.

  7. Point-to-Multipoint Topology

    • Structure: Central wireless base station connects to multiple other wireless locations.
    • Usage: Common in wireless outdoor networks.

  8. Peer-to-Peer Topology

    • Structure: All clients can communicate and share resources directly with each other.
    • Usage: Common in homes and small businesses; easy to set up.

Connectors

  1. RJ-11 Connector

    • Usage: Telephone equipment and modems. Locks with a single tab.

  2. RJ-45 Connector

    • Usage: Connects computers to LAN. Features 8 wires and is larger than RJ-11.

  3. RJ-48C Connector

    • Usage: Used with shielded twisted pair for T1 lines.
    • Difference: Similar to RJ-45 but uses shielded cables.

  4. UTP Coupler

    • Usage: Connects UTP cables with RJ-45 connectors when long cables are not an option.

  5. BNC Connector

    • Usage: RF connectors on coaxial cables; used for both analog and digital video and audio.

  6. Fiber Coupler

    • Usage: Joins two identical fiber optic connectors (e.g., ST, SC).
    • Note: Not to be confused with fiber adapters (joins different connectors).

  7. F-Type Connector

    • Usage: Threaded connector for coaxial cables; used by cable providers.

  8. USB Connector

    • Usage: Very common; used for network cards, peripheral devices.
    • Types: Type A and Type B.

  9. IEEE 1394 (FireWire) Connector

    • Usage: Attaching peripheral devices (cameras, printers) rather than network connections.
    • Shape: Recognizable by its D shape.

  10. MTRJ Connector

    • Usage: Latched, push-pull fiber optic connector for high-density applications.
    • Full Form: Mechanical Transfer Registered Jack.

  11. ST Connector (Straight Tip)

    • Usage: Commonly used with single-mode fiber optic cable; uses a half-twist lock.

  12. LC Connector (Local Connector)

    • Usage: Fiber optic connector; commonly used between building floors.

  13. SC Connector (Standard Connector)

    • Usage: Push-pull connector for fiber optics; similar to audio/video plugs.

Cables and Standards

  1. Serial Cables

    • Function: Carry serial data transmission (one bit at a time).
    • Standard: RS-232, commonly using DB-9 or DB-25 connectors.

  2. Ethernet Over HDMI (IEEE 1901)

    • Function: Adds a data channel to HDMI cables for network communication (100 Mbits/s).

  3. Ethernet Over Powerline

    • Function: Uses existing electrical wiring for Ethernet networking via Powerline adapters.

Networking Standards and Technologies

  1. IEEE 802.11 (Wi-Fi)

    • Year Standards: 802.11A (1999), 802.11AC (2014), etc.
    • Characteristics: Varied speed and frequencies.

  2. Infrared (IR)

    • Usage: Data transmission via light rays; requires direct line of sight.
    • Drawbacks: Obstructed by objects, sunlight affects communication.

  3. Bluetooth

    • Usage: Short-range radio for voice and data exchange.
    • Specs: Speed up to 24 Mbits/s, range up to ~100 meters.

  4. Geo-Specific standards like GSM, CDMA, 3G, 4G LTE

    • GSM: Time slot-based digital signal.
    • CDMA: Data encoded with a unique key.
    • 3G/4G LTE: Increased speed, with 4G LTE over 100 Mbits/s.

Network Troubleshooting

  1. Link LEDs

    • Green LED: Indicates a network connection.
    • Yellow Blinking LED: Indicates network activity.
    • Unlit Link LED: Possible issues include bad cable or NIC not functioning.

  2. Steps to Solve Network Problems

    • Identify Symptoms and Potential Causes
    • Identify Affected Area: Isolated or wide-spread issue?
    • Establish What Changed: Hardware/software addition/removal?
    • Select Probable Cause: Look for simple solutions first.
    • Implement Action Plan and Solution
    • Test Result: Does the plan resolve the problem?
    • Document Solution: Note down problem, cause, and fix for future reference.

Command Line Utilities

  1. Ping

    • Usage: Test connectivity and DNS name resolution.
    • Command: ping [host/IP]

  2. Tracert (Traceroute)

    • Usage: Finds the path data takes to reach a destination.
    • Command: tracert [host/IP]

  3. Netstat

    • Usage: Displays current network connections.
    • Command: netstat

  4. Ipconfig

    • Usage: Displays network configuration details.
    • Command: ipconfig /all

  5. Nslookup

    • Usage: Looks up DNS information for a domain.
    • Command: nslookup [domain name]

Network Security

  1. Firewalls

    • Function: Prevents unauthorized access by filtering network traffic.
    • Types: Host-based (protects one computer), network-based (protects an entire network).
    • Access Control List (ACL): Controls the flow of traffic through allow/deny rules.

  2. VPN (Virtual Private Network)

    • Usage: Establishes secure remote access over a public network.
    • Types: Site-to-Site, Host-to-Site, Host-to-Host.

  3. Authentication Protocols

    • PAP: Simple but insecure, uses clear text.
    • CHAP: Secure with three-way handshake and encrypted passwords.
    • Kerberos: Uses tickets for authentication.

  4. Wireless Security Protocols

    • WEP: Weak encryption, easily hackable.
    • WPA: Uses TKIP, more secure than WEP.
    • WPA2: Uses CCMP for stronger encryption.
    • WPS: Simplifies connection but known vulnerabilities.

Network Components and Tools

  1. Routers and Switches

    • Router: Routes data between networks using IP addresses.
    • Switch: Connects devices within a network, forwards data to specific destinations.
    • Smart/Content Switches: Advanced functions (e.g., load balancing, filtering).

  2. Bridges and Hubs

    • Bridge: Filters data on MAC addresses, reduces unnecessary traffic.
    • Hub: Sends incoming data to all ports; lacks intelligence compared to switches.

  3. Transceivers and Wireless Access Points

    • Transceiver: Transmits and receives data.
    • Wireless Access Point: Bridges wireless and wired devices.

  4. Tools and Testers

    • Crimper: Attaches connectors to cables.
    • Punch Down Tool: Connects wires to a punch-down block.
    • Media Tester: Tests cable integrity.
    • Multimeter: Measures voltage, resistance, continuity.
    • Protocol Analyzer (Packet Sniffer): Analyzes network traffic; e.g., Wireshark.

Environment and Safety

  1. ESD Protection

    • Wrist Strap: Grounds user to prevent component damage.
    • ESD Mat: Provides a grounded work surface.

  2. Proper Disposal

    • MSDS: Guides on safe disposal of hazardous materials.

  3. Safety Precautions

    • Power Off Before Repair: Prevents electrical shocks.
    • Hand Jewelry Removal: Avoids conduction hazards.
    • Cable Management: Reduces tripping hazards.
    • Proper Lifting Techniques: Prevents physical injury.

Virtualization and Cloud Computing

  1. Virtualization

    • Definition: Running multiple virtual servers/applications on one physical server.
    • Types: Virtual Switch, Virtual Router, Virtual Firewall.
    • Benefits: Cost-saving, less hardware, easier management.

  2. Cloud Computing

    • Definition: Data and applications are stored and run on remote servers, accessed via the internet.
    • Types: IAAS (Infrastructure), PAAS (Platform), SAAS (Software).
    • Examples: Email (Gmail), Productivity Software, Web Services (Amazon Web Services).

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